Artificial leg



UNITED sTATEs `PATENT oFrioE.

O. D. WILCOX, OF EASTON, PENNSYLVANIA.

ARTIFICIAL LEG'.

Speccation of Letters Patent No. 15,831, dated September 30, 1856.

To all whom t may concern.'

Be it known that I, O. D. WiLoox, M. D., of Easton, in the county of Northampton certain newand useful Improvements in the Construction of Artificial Limbs; and I do hereby declare that` the following is a full, clear, and exact description of the same and to the accompanying drawings, making a l part of this specification.

The limb is beams@ of iight `Wood Such as willow, covered with white `paintor varnish. The drawings exhibit it partly in section the better to enable others skilled in the `art to construct the same.

the leg and foot are efected and controlled.`

Second, in the form and construction of the kne-e and ankle and their joints, by which such as required in bending the knee in the act of kneeling, squatting orV sitting, in a carriage; also in givingthe" requisite movement of the foot in ascending a hill or stepping on any inequality.

Third, in providing a support for `the st-ump by the employment of a sack suspended from the upper edge of the artificial thigh, by which an equal pressure on all parts of the stump is obtained and an equality of circulation of the blood maintained thereby overcoming a ditliculty experienced in other artificial limbs wherein the stump being forced into a conical socket to support the weight of the patient and not properly supported or pressed upon its lower end, strangulation of the blood ensues. An attempt has been made, by a pad and spiral springsto obviate this evil, butnot successfully.

Fourth, by the employment of check stops at the knee joint I get rid of the unpleasant noise, on the mot-ion of the limb.

The advantages of my mode of construction gives me a limb, that is light and yet strong and by the leg entering the thigh it affords substance of wood for sustaining the bolt at the knee, while by the employment of the'elastic cord and pulley, the motions of the limb are more naturally produced and the sole of the foot brought more Hat or level with the earth irrespective of the inclination thereof.

or cord. greater `.flexion of those joints is obtained,

To enable others skilled in the art to con- 1 struct the limb I would describe it as folj lows.

and State of Pennsylvania, have invented `lindrical of light wood and fitsthe stump A represents the thigh. -It is made cyof the limb, it is provided with a bottom b 1 near its lower edge to which the tendon, and check straps are secured.

its mode of operation, reference being had limb exhibiting by a line the shape of the In Figure l, is shown the exterior of the lower edge of the thigh.

` In Fig' 3 is Shown the metal straisnor` u hinge plate of the knee and ankle. v j j B, is the leg, formed partially hollow.` At the knee it is left'solid asshown in the shade lines so as to give firmness to the 1 screw bolt` (a') passing through it, and sup- `port to the pulley. The bolt and plates on the thigh form the knee joint. At its lower end it is also formed solid as shown at (d) except perforations for passing the tendon,

c, is the foot containing within `its nhollow asolid portion (e) forming a half pulley around which the tendons giving motion to the foot, partially wind and unwind The toe piece is secured by simply fastening a thick piece of leather as a hinge on the sole, and a spiral spring is placed in the wedged shaped opening. i

The supports to the joints of the knee and ankle are formed of thin metal plates g and Z riveted one to the thigh and the other to the foot. The bolts (a and a) pass through those plates and form the joints. The holes in the leg should be bushed with metal.

I is a stop block at the rear of the joint and K a similar block in front of the ankle joint of the foot. (L, is a spring secured on the latter block whose office will be presently explained.) TheseV blocks I and K control the motions of the foot by coming in cont act with the front or rear end of the leg, as the foot is moved.

P, is a pulley working in a slot formed in the solid portion of the leg at the knee. Over it the tendons pass or roll.

M is one of the tendons and M, its muscle, corresponding to the extension; and N and N the second muscle and tendon, corresponding the achilles. `The upper end of M and N are secured rmly to the thigh by being passed through the bottom thereof. They extend over the pulley P, the one in front, the other in the rear of it, down through the leg, then overthe half pulley e,

Y one end secured in the bottom of the thigh,

and the v other passing loosely over the rounded end of the leg (see Fig. 2) and secured by small screws to the back thereof. Those straps check or control the movement of the leg when straightened.

The spring L in the foot is introduced, to prevent t-oo free a movement thereof, under t-he influence of the muscle, and when the limb is used in ascending a hill for instance whenthe knee is thrown far forward, or when the front ofthe foot is accidentally placed on a stone,` then this spring is beautifully brought into use. Under ordinary circumstances of walking on a level, it is not usually brought into play more than as an easy check.

In joining the leg to the thigh it will be noticed that the leg is inserted in the thigh, by which its strength is maintained, its movement more in conformity with the natural limb, and freedom from catching the clot-hes of the wearer. The lower end of the leg is inserted into the foot with the same advantages.

The sack O is made of any suitable material its size so as to freely embrace the natural stump and of just sufficient depth that the end of the stump may be pressed thereby being fastened, stitches or otherwise, to the upper edge of the thigh piece A. The weight of the body is as it were suspended in the sack. By the employment of this sack, it has been found that ventilation of the limb is not required as the circulation of blood through the stump is very slightly affectcd.

What I claim as my invention and desire to secure by Letters Patent is:

l. 'Ihe employment of the pulley P at the knee joint as a common center of motion, of the elastic cords M M and N N as described for the purpose of producing a natural movement of the artificial limb in the manner set forth.

2. I also claim the employment of the 'sack O, whether used in this limb or any other.

In testimony whereof I have hereunto signed my name before two subscribing witnesses.

O. D. WILCOX.

Witnesses:

JOHN F. CLARK, JOHN S. HoLLINGsHEAD. 

